Water-tube boiler



A. COTTON WATER TUBE BOILER F i106 Harh 15, 1920 Feb; 2, 192s. 11,511,369

3,6/ @KM #Www/S Patented F eb. 2, 1926.

ED S 1,571,369 Parels'r or Fics..

ALFRED COTTON, 0F ST. LOUIS, MISSOURI, ASSIGNOR TO 4I-IllINlll BOILER COMPANY, OF.

ST. LOUIS, MISSOURI, A CORPORATION OF MISSOURI.

WATER-TUBE BOILER.

Application lediMarCh 15, 1920. Serial No. 365,808.

To all whom t may concern.'

Be it` kno-Wn that I, ALFRED COTTON, a citizenof the United States, residing at St. Louis, Missouri, have inventeda certain new Vand useful Improvement in lVater- Tube Boilers, of which `the Vfollowing is a full, clear, and exact description, such as will enable others skilled in vthe art to which it appertains to make and yuse the same.

This invention relates to Water tube boilers of the ,type in which the tubes are arranged horizontally, or substantiallyso, such, for example, as in the Heine boiler noiv in general use.

The main object of the invention is to provide an efficient boiler of .the general type referred to that can be operated Vsuccessfully with gases `of a lower temperature thanthe gases obtained by direct Vtiring, thus producing a boiler that can be operated by the heat obtained from the incineration of municipal refuse or from Waste heat from industrial processes, such as cement kilns, puddling furnaces, etc.

Another object is to provide a. Water tube boiler of the horizontal type which is so designed that the draftresista-nce andthe velocity of the gases are relatively high; which permits the gases to `be taken oil either from the top or 'from the bottoni of the yboiler, and Whose efciency Will not be reduced by the accumulation of dust on the heating surface or on the baffles of theboiler.

To this end I have .devised a -boiler provided with horizontal, or substantially horizontallylisposed Water tubes, and transversely-disposed obstructions or bailles combined With said tubes in such a manner that the entire-tube bank constitutes a single longitudinal pass through Which-the gases flows in a number of zig-zag or sinuous streams, one above the other and each eX- tendingacross the entirev Width of the bank, the general direction oftlow of saidstreams being substantially .parallel to or lengthwisel of the tubes.

Figure l is Aa vertical longitudinal sectional vieiv, of a boiler constructed in accordance with my invention; and

Figure 2` is a vertical longitudinal sectional view ofasuperheater boiler embody- .ing my invention.

vthe Lgases enter the boiler Zhen aiboiler is operated bydirect firing, at a temperature close to that of the lire and muchof the -heat Iistransmitted by radiation. Itis Well known that the rate of heat `transferred from thegases tothe Water per unit ofheating/surface is greater as the velocity of `the gases is increased. I `have found `that Lin boilers which are adapted to be operated by Waste heat or low temperature gases it is i outlet located at the top of the boiler; andA because the dust which is valways present in considerable quantities in waste gases will settle on-the heating surface and on'the battles, thus cutting down the efliciency of the boiler and clicking the gas passages to such anvextent that the flow of the gases is materially retarded. Attempts have been made to remedy this defect ofv conventional Water tube'boilers of the horizontalrtype by arrangingthe gas outlet at the bottom of .the boiler, by omitting baffles in the tube bank and by providing the boiler With a hopper for collecting the dust that settles out'ofthe gases in the passage of the gases through the boiler, and While a boiler of the kind just mentioned permits the gases to be ,At/aken from an outlet at the bottom of the' boiler and prevents dust from accumulating on the tubes, it is not entirely satisfactory, due to the relatively low velocity of the gases andV to the fact that the gases follow such a path that they do -notcome in direct contact with, much ofthe hea-ting surface o f the boiler. In instances VWhereit Was sought to reduce the gas passage area and increase Ithe velocity of the gases by ,arranging horizontally-idisposed batlies in theftube bank, it Was foundfthat thedustcollected on the baffles and tubes fin suoli quantities as to materially cut down that follow several tortuous or sinuous the etliciency of the boiler `and retard the passage of the gases through same.

My improved boiler has none of the ob jectionable characteristics of boilers of the kind above described.

(lst) It is not restricted to an outlet at the top of the boiler for the escape of the gases; n

(2nd) It is of such design that 1t has'a high draft resistance and the gases will travel through the boiler with a high velocity;

(3rd) It is provided with a means for obstructing the flow of the gases which is of such a character that the dust which settles out of the gases will not accumulate on the heating surface of the boiler or on baffles arranged in the path of travel of the gases; and

(4th) It is so constructed that the gases will impinge upon or come in direct contact with substantially the entire heating surface of the boiler. Accordingly, my improved boiler can be successfully operated by waste gases or by direct firing with powdered coal.

In Figure l of the drawings I have'illustrated one form of water tube boiler embodying my invention. Said boiler is provided with a single longitudinal gas pass having transversely-disposed obstructions, or partitions arranged in same in such a manner that the entire tube bank constitutes a single longitudinal pass through which the gases flow, longitudinally of the tubes, in a number of undulating, superimposed streams, each of which extends the entire width of the pass, thus causing the gases to follow several tortuous or sinuous paths approximately parallel to the water tubes l. By constructing the boiler in the manner just referred to I obtain a high draft resistance and a high velocity of the gases. The battles or obstructions can be arranged in various ways to accomplish the results above described without departing from the spirit of my invention, but in all instances the tube bank will be equipped with a number of vertically-disposed battle elements arranged transversely of the tube bank, one behind the other, and disposed so as to co-operate with each other to virtually form a number of transverse baffles provided with solid portions and openings disposed so as to cause the gases to low longitudinally of the boiler tubes in wave-like or undulating paths, as indicated by the arrows in Figure 1. In the form of my invention illustrated in Figure l the baile elements just referred to are formed byl groups of relatively shallow, vertically-disposed battles A and B arranged transversely of t-he boiler tubes l so as to cause the gases to How in several superimposed undulating streams paths, as indicated by the reference character m in Figure l. Each group A comprises several batlles arranged edgewise or vertically at different levels'in the tube bank'and each group B comprises several battles arranged edgewise or vertically at different levels in the tube bank, the baffles constituting each of said groups having their horizontal edges spaced apart so as to form .horizontally-disposed openings that extend across the entire width of the tube bank through which the gases flow. The battles of the various groups A and B can either be arranged in vertical alignment, one above the other, or they can be arranged in echelon, as shown in Figure l, the battles constituting the groups B being arranged between the battles constituting the groups A and opposite the spaces or openings between the horizontal edges of the baffles constituting the groups A so that ythe gases which flow through the openings between the baffles of the groups A will divide upon encountering the battles B and flow upwardly and downwardly over said battles B. While I prefer to arrange the baliles A and B so that hori zontally-disposed spaces orV openings areJ formed between the battles constituting each of said groups, this is not essential, so long as openings in the verticallydisposed, transverse battle elements in the tube bank are so arranged or formed that the gases lwill flow in tortuous or sinuous paths longitudinally of the tube bank. Instead of using separate shallow members to -forni the battles, a number of relativelylarge, vertically-disposed battle members provided with openings could be arranged transversely of the tube bank, one behind the other, the openings in each battle member being so disposed with relation to the solid portions of the two baille members between which it is positioned that the gases will tollen' the paths or approximate paths indicated by the reference character ai in Figure l.

By constructing a water tube boiler of the horizontal type in the manner above described I avoid eddies and dead gas pockets at the down stream side ofthe tubes, as occurs when water tube boilers of the horizontal type are equipped with transversely-disposed batlles arranged so that the gases travel transversely across the tubes through a number of seria-l passes, for in my improved boiler the direction of the How of the gases relative to the tubes of the boiler is from a parallel to an oblique line. In my boiler the eddies which tend to form behind the battles are taken advantage of to insure the impingement of the gases on the whole of the heating surface of the boiler. Another desirable feature of my boiler is that the effective area ofJ gas passage and consequently the average velocity of the gases can be accurately regulated and controlled by adjusting the size of the battles and the area of the spaces between or through the bailles. I believe that the rate of heat transier is directly related to the pressure drop or draiit drop of the system, and it is obvious that I can attain any amount oi obstruction or draft resistance by suitably proportioning and arranging the battles of my boiler.

I prefer to make the bailles of such size that they approximate the size oi the openings lett between the previous bailles, so that the direction of iiow is not brought too near to right angles. I also prei'er to construct the boiler in such a manner that approximately 3,000 to 5,000 pounds ot' gas will ilow through each s uare toot of' gas passage area per hour. In ligure 2 ot the dra-wings I have illustrated a superheater boiler constructed in accordance with my invention, said boiler being provided with battles A and B of the kind shown in Figure l, and also a. superheater C ot any preferred construction arranged in a super-heater chainber through which a portion ot the gases travel. Instead ot arranging the superheater C so that it will be heated by only a portion of the gases that pass through the boiler, the superheater could be arranged 1n such a manner that it will be heated by all oit the gases passing through the boiler. In both forms oi my invention represented by Figures l and 2 hoppers or other suitable devices 7 are. provided itor collecting the dust that settles out ot the gases, and while the gas outlets 5 are preferably located at the bottom of the boiler, this is not essential, as the outlet could be located at the top ot the boiler. I have not illustrated any means tor inducing a circulation oiI the gases through the boiler, but in practice when my improved boiler is used for utilizing waste gases, a ian or other suitable suction device is connected with the gas discharge outlet 5 of the boiler.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent, is:

l. A water tube boiler provided with a tube bank composed of substantially horizontally-disposed water tubes, and verticallydisposed, transverse baille elements arranged transversely of the tube bank, one behind the other, and constructed to iorm solid portions and openings that are disposed so as to cause the gases to split up into a plurality of streams and flow in tort-nous lor sinuous paths approximately parallel to the tubes constituting said bank.

2. A boiler provided with a tube bank composed of substantially horizontally-disposed water tubes, a group of verticallydisposed, transverse baille elements arranged in said tube bank, one behind the other, and each constructed to form a plurality of solid portions and openings between said solid portions through which the gases flow, and a separate group ot vertically-disposed transverse battle elements arranged in the tube bank between the baille elements constituting said first group and provided with similar solid portions and openings arranged in staggered relation with those of the baille elements of said ilrst group.

3. A water tube boiler provided with a tube bank composed of substantially horizontally-disposed water tubes, and vertically-disposed baille elements arranged transversely ot the tube bank, one behind the other and each contructed to form solid portions and openings disposed in such relation to the solid portions and openings of the other baille elements as to cause the to split up into a plurality of streams and flow in tortuous or sinuous paths approximately parallel to the tubes constituting said bank, and means for collecting particles of dust or other matter that settle out oi the gases while the gases are traveling through the tube bank.

l. A boiler provided with a tube bank composed oit substantially horizontally-disposed water tubes, a group oit' verticallydisposed baille elements arranged transversely of the tube bank, one behind the other and each composed ot a plurality et relatively shallow battles arranged at di iterent levels in the tube bank and having their horizontal edges spaced apart so as to form openings througlrwhieh the gases ilow, and an independent group of vertically-disposed baille elements arranged transversely of the tube bank between the battle elements oi said iirst group and composed ot similarly arranged shallow battles that are disposed in staggered relation with the shallow battles oit said iirst group.

ALFRED COTTON. 

